1. Field of the Invention
The present invention relates to an air bag device for an automotive vehicle, and more particularly to an air bag device which is installed in a space inside an instrument panel or a dashboard so as to protect an occupant of a passenger seat in a front passenger compartment during a collision of the automotive vehicle. The air bag is inflated from a folded state in a reaction can during the collision.
2. Description of the Related Art
In general, an air bag device, for protecting the passenger sitting on the passenger seat, is installed in the instrument panel. The air bag device has an air bag module for holding the air bag and its ignition equipment in an air bag case. The air bag device also includes an air bag lid for covering an opening formed in the instrument panel. The air bag lid is opened by the pressure of the air bag when the air bag is inflated.
In the above air bag device, when the automotive vehicle decelerates at some value above a predetermined value, an impact sensor detects a sudden deceleration of the vehicle. The signal from the impact sensor causes the ignition equipment to operate so that the air bag inflates to protect the passenger.
However, in some situations the vehicle decelerates at a value which is smaller than that necessary to trigger inflation of the air bag. In this case, it is possible that the passenger could hit their head on the instrument panel or the air bag lid. Thus, it is desirable to make a large space in the instrument panel so as to position the air bag module away from the air bag lid thereby protecting the passenger from the air bag module in the above situation.
Japanese Unexamined Laid-open Patent Application 2-155855 discloses an air bag device wherein a number of slots are formed in the side walls of the air bag case for absorbing the impact. Thus, this reference proposes that the air bag module can be positioned near the air bag lid and both the air bag lid and the instrument panel can absorb the impact by their deformation.
However, even though it is possible to locate the air bag module near the inner surface of the instrument panel in the above prior art, this design requires slots in both side walls. This structure requires increased manufacturing time and expenses to make the side walls as well as in selecting the shape of the slot and the material of the air bag.